s recommendations, but in no case will more than 18 initiating devices be interconnected (of which 12 may be smoke alarms) where the interconnecting means is not supervised, nor more than 64 initiating devices be interconnected (of which 42 may be smoke alarms) where the interconnecting means is supervised.

NFPA 72-1999 8-4.2 All monitored circuits will indicate with a distinctive trouble signal the occurrence of a single open or single ground fault.

"power supplies,...
NFPA 72-1999 8-4.1 The two independent power sources will consist of a primary source that uses the commercial light and power source and a secondary source that consists of a rechargeable battery or standby generator that can operate the system for at least 24 hours in the normal condition followed by 4 minutes of alarm.

NFPA 72-1999 8-4.5 Smoke alarms will be powered from the commercial light and power source along with a secondary battery source that is capable of operating the device for at least 7 days in normal operation followed by 4 minutes of alarm. Alternatively, smoke alarms will be powered by a non-replaceable primary battery that is capable of operating the device for at least 10 years followed by 4 minutes of alarm, followed by 7 days of trouble.

NFPA 72-1999 8-4.6 Smoke alarms powered by a primary battery capable of operating the device for at least 1 year in normal operation followed by 4 minutes of alarm, followed by at least 7 days of trouble, will be used only when specifically allowed.

"performance,...
NFPA 72-1999 8-1.2.1 Sufficient initiating devices shall be installed within the dwelling unit so that their operation provides adequate egress time before the occurrence of untenable conditions at any point along the normal path of egress for all design fire scenarios specified in applicable codes and any supplementary fire scenarios specified by the authority having jurisdiction.

NFPA 72-1999 8-1.4.3 Smoke alarms and smoke detectors will be capable of detecting abnormal quantities of smoke and will alarm prior to a gray smoke level of 4 percent per ft. Visible notification appliances located on the ceiling over the bed and within 16 feet of a sleeping occupant will have a light output rating of 177 cd. Where a visible notification appliance in a sleeping room is mounted more than 24 inches below the ceiling and within 16 feet of the pillow, a minimum rating of 110 cd will be permitted.

"spacing and location of detectors...
NFPA 72-1999 8-1.4.1.6 One- and Two-Family Dwellings. Approved single-station smoke alarms will be installed in the following locations:
(1) All sleeping rooms (in new construction).
(2) Outside of each separate sleeping area in the immediate vicinity of the sleeping rooms.
(3) On each additional story of the dwelling unit including basements. (Approved smoke alarms powered by batteries will be permitted in existing construction).

"and alarm sounding devices."
NFPA 72-1999 8-1.2.2 Fire warning equipment for dwelling units shall provide a sound that is audible in all occupiable dwelling areas. Audible fire alarm signals shall meet the performance requirements of NFPA 72-1999 4-3.4. If the dwelling unit is occupied by people with hearing deficiencies, visible appliances shall be provided in all dwelling areas to meet the requirement of Section 4-4.

NFPA 72-1999 4-3.3 Private Mode Audible Requirements. Audible notification appliances intended for operation in the private mode will have a sound level of not less than 45dBA at 10ft (3m) or more than 120dBA.
To ensure private mode signals are clearly heard, they will have a sound level at least 10dBA above average ambient sound level or 5dBA above maximum sound level having a duration of at least 60 seconds, whichever is greater, measured 5 ft (1.5m) above the floor in the occupiable area.
Where audible appliances are installed to in sleeping areas, they will have a sound level of at least 15dBA above average ambient sound level or 5dBA above the maximum sound level having a duration of at least 60 seconds or a sound level of 70dBA, whichever is greater, measured at the pillow level in the occupiable area.

NFPA 72-1999 8-1.2.3 Newly installed fire warning equipment for dwelling units (including self-contained devices) will produce the audible emergency signal described in ANSI S3.41, Audible Emergency Evacuation Signal. (AKA 3-pulse temporal pattern fire alarm evacuation signal)
(a) A fire alarm signal will take precedence or be clearly recognizable over any other signal even when the non-fire alarm signal is initiated first.
(b) Distinctive alarm signals will be used so that fire alarms can be distinguished from other functions such as burglar alarms. The use of a common sounding appliance for fire and burglar alarms will be permitted where distinctive signals are used. (See 2-2.2.2)

THE INFORMATION HEREIN IS PROVIDED AS A GUIDE ONLY AND IS INTENDED TO ASSIST YOU IN PREPARING FOR AN EXAM. IT IS NOT INTENDED TO BE INCLUSIVE OF ALL INFORMATION THAT MAY BE ON AN EXAM BUT RATHER IT IS INTENDED TO BE A SMALL SAMPLE OF THE KIND OF MATERIAL THAT YOU MAY BE EXPECTED TO KNOW.